Stepper carriage advancement system

ABSTRACT

An advancement mechanism for horizontal earth boring machinery which can automatically advance or retract the boring unit without independent manipulation of the locking unit associated with the advancement mechanism. The device comprises a set of dogs pivotally mounted on the advancement mechanism so as to engage rails provided to support the earth boring equipment. A variable volume pump is employed with a hydraulic cylinder to alternately advance the earth boring machine and the advancement mechanism. Further, a lever is employed which has the capability of automatically switching the direction of flow of the hydraulic pump to enable the progression of the total unit to be completely automatic.

Halted tates ate Century Mar. 11, 1975 154] STEPPER CARRIAGE ADVANCEMENTSYSTEM [22] Filed: Sept. 11, 1972 [21] Appl. No.: 287,782

[52] US. Cl 254/105, 74/110, 74/527, 104/147 R, 105/29 R, 105/31,105/32,

[51] Int. C1.B23g 5/26, B6ld /00, F16h 21/44 [58] Field of Search104/147,162,163,147 R; 105/29 R, 30, 31, 32, 161; 173/24, 46, 141,

2,740,358 4/1956 Philbrick 280/30 2,833,531 5/1958 Joy 299/31 3,040,6776/1962 Crccdle 105/31 3,121,560 2/1964 Rccd 280/1045 A X 3,190,3716/1965 Maxwell 173/141 3,682,261 8/1972 Bird 175/122 PrimaryErtuniner-Lloyd L. King Assistant Examim'rHOWard Beltran Attorney,Agent, or Firm-Lyon & Lyon [57] ABSTRACT An advancement mechanism forhorizontal earth boring machinery which can automatically advance orretract the boring unit without independent manipulation of the lockingunit associated with the advance ment mechanism. The device comprises aset of dogs pivotally mounted on the advancement mechanism so as toengage rails provided to support the earth boring equipment. A variablevolume pump is employed with a hydraulic cylinder to alternately advancethe earth boring machine and the advancement mechanism. Further, a leveris employed which has the capability of automatically switching thedirection of flow of the hydraulic pump to enable the progression of thetotal unit to be completely automatic.

6 Claims, 9 Drawing Figures PATENTED NARI 1 I975 SHEET 1 0f 3 E MENTED 11975 3.870 279 saw 3 or 5;

STEPPER CARRIAGE ADVANCEMENT SYSTEM This invention relates toadvancement mechanisms for horizontal earth boring machines. Morespecifically, this invention is directed to an improved means forlocking and unlocking the advancement mechanisms during the walkingprocess and for controlling the walking process using the improvedlocking means. Heavy-duty, horizontal earth boring equipment generallyrequires mechanical means for driving the boring unit and auger into andout of the intended horizontal shaft. To accomplish this, a rail orrails have been employed. These rails provide the means for aligning theunit as well as provide the base from which force is applied to bothadvance and retract the boring unit from the shaft. Advancementmechanisms have been among the methods employed to advance and retractthese boring units along the rails. A advancement mechanism is operatedby first anchoring it to the track to provide a base for forcing theboring unit either toward or away from the shaft along the rails. Whenthe boring unit has been moved the predetermined distance, theadvancement mechanism is disengaged from the track and drawn along tothe next position. This sequence is then repeated for as many times asrequired to cross the desired distance.

Advancement mechanisms heretofore employed to both advance and retractthe boring units have required specific separate operations to eitherengage or disengage the advancement mechanism during each cycle. Thisseparate independent step requires the operator to stop the walkingprocess of eachcycle to either engage or disengage the advancementmechanism. This procedure necessarily slows the overall process ofdrilling a shaft. Further, the walking process cannot be totallyautomated using this separate engagement step without excessivemechanical complication.

An object of the present invention is to provide a advancement mechanismfor a horizontal earth boring machine which will automatically engageand disengage itself from the supporting rails during the walkingprocess. This walking process can be accomplished in either direction.Rail engaging dogs are provided which, when unconstrained, are free tomove from engagement with the rails. Selective constraint means areprovided which prevent the dogs from disengaging when the advancementmechanism is moved in either one or both directions along the rails.Because the dogs can be selectively constrained from disengagement in agiven direction, the advancement mechanism will automatically disengage,advance, and lock in each succeeding position as required.

A second object of the present invention is to provide an automaticadvancement mechanism which will selectively allow the walking processto be performed in either direction along the rails. Because of theselective constraint means, the advancement mechanism can be made toautomatically perform the cycle of disengagement, advancement, and lockfor both advancement and retraction along the rails. Thus, a directionof walking is first selected. The advancement mechanism is then drivenby a hydraulic cylinder to perform its function without furtherindependent manipulation of the locking means.

A further object of the present invention is to provide a practicalmeans for automatically actuating a cylinder or other device which isused to alternately force the advancement mechanism toward and then awayfrom the boring unit to accomplish the walking process. Because theoperation of the advancement mechanism has been automated through thepresent invention, a further advantage is obtained. The walkingoperation may be totally automated with little or no further mechanicalcomplication using a variable volume pump to drive a hydraulic cylinderand a simple control lever.

Thus, a advancement mechanism is herein disclosed which automaticallylocks and unlocks to accomplish the walking process and provides foreasy adaptation to a wholly automatic advancement system for ahorizontal earth boring machine. Further objects and advantages willbecome apparent from the description herein.

FIG. 1 is a side view of the horizontal earth boring unit and theadvancement mechanism.

FIG. 2 is a top view of the advancement mechanism and the attachedhydraulic cylinder.

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2.

FIG. 4 is a cross-sectional view taken along line 4-4 'of FIG. 3.

FIG. 5 is a top view of the advancement mechanism shown in the advancingmode.

FIG. 6 is a top view of the advancement mechanism shown in theretracting mode.

FIG. 7 is a top view of the control arm and lock taken along the line7-7 of FIG. 1.

FIG. 8 is an enlarged view of the part of the apparatus shown in FIG. 1.

FIG. 9 is a view of the part of the device shown in FIG. 8.

Turning now to the drawings, FIG. 1 schematically illustrates theemployment of the automatic advancement mechanism 10 with the horizontalearth boring unit 12. Theunit 12 is shown with an auger 14 in position.Rails 16 are provided to support and guide the total assembly. Theautomatic advancement mechanism 10 includes a base plate 22 whichsupports the advancement mechanism 10 on the rails 16. The advancementmechanism 10 also is capable of selectively engaging the rails 16 atengaging means here provided by slots 20. A double acting hydrauliccylinder 18 extends between the horizontal earth boring unit 12 and theadvancement mechanism 10 which is capable of acting in combination withthe engagement mechanism of the advancement mechanism 10 to force thehorizontal earth boring unit 12 in a plurality of steps along the rails16.

The automatic advancement mechanism 10 is best illustrated in FIGS. 2through 6. The advancement mechanism 10 has a base plate 22 which issupported on rails 16. Support members 24 are welded to the base plate22 and add structural rigidity to the unit. Structural members 24 areextended to form brackets 26 and 28 for coupling the hydraulic cylinder18 to the advancement mechanism 10. A circular hole 30 is provided ineach bracket 26,and 28 for the location of pin 32. The cylinder 18 hasan eye member 34 which fits between brackets 26 and 28 to cooperate withpin 32. Locking pins 36 and 38 keep pin 32 in position. The base plate22 is provided with two notches 40 and 42 to accommodate brackets 26 and28. The base plate 22 is further supported by plates 44 and 46 which arewelded to the base plate 22 and the structural members 24. Plate 48 isprovided between brackets 26 and 28 for further support.

Locking members and 52 are provided to keep the advancement mechanism 10from lifting off the track 16. Pins 54 and 56 tightly fit into brackets58 and 60 which are in turn welded to the base plate 22. Pivoted arms 62are allowed to rotate about pins 54 and 56. Plates 64 extend betweenarms 62 and are welded thereto. Locking members 66 extend under therails 16 to prevent the advancement mechanism 10 from lifting off therails 16. Studs 68 are rigidly fixed to the base member 22. Plates 64fit over studs 68. Locking pins 70 prevent the locking assemblies 50 and52 from rotating into a disengaged position because of the interferencebetween plates 64 and pins 70.

Means are provided for engagement of the advancement mechanism 10 withrails 16. Such means must allow for disengagement as the advancementmechanism 10 is moved along the rails and further provide for a means ofconstraint to selectively prevent disengagement. One device foraccomplishing this function is provided by dogs 72. Dogs 72 arepivotally mounted rigid members attached to the advancement mechanism 10through pins 74 and 76 respectively. The pins 74 and 76 are rigidlyfixed to the dogs 72 and rotate therewith. The pins 74 and 76 rotate inguide members 78 and 80 and in the base plate 22. The guide members 78and 80 and in the base plate 22. The guide members 78 and 80 extend thelength of the advancement mechanism 10 to keep the advancement mechanism10 aligned on the rails 16. Washers 82 and 84 space the dogs 72 from theadvancement mechanism structure 10 and provide bearing surfaces for therelative rotation between the advancement mechanism 10 and the dogs 72.The indicators 86 and 88 are provided above the base plate 22 toindicate the angular position of the dogs 72. The indicators 86 and 88further provide a thrust surface for the washers 82. Nuts 90 areprovided to lock the pins 74 and 76 in place. The dogs 72 are positionedto engage slots 20 provided in rails 16 and are pivoted to allowdisengagement from the rails 16 as shown in FIGS. 5 and 6. To providepositive engagement action by the dogs 72, springs 92 and 94 areprovided. Eye bolts 96 anchor the springs 92 and 94 to the dogs 72, andbrackets 98 and 100 provide attachment to the structure of theadvancement mechanism 10.

To determine the direction of travel of the advancement mechanism 10,means must be provided to work in conjunction with the engagement meansor dogs 72 to selectively constrain the dogs 72 from disengagement whenthe advancement mechanism 10 is forced in a given direction. One form ofconstraining means which is conveniently operated in conjunction with asingle actuation member is provided by dog extensions 102 and a seriesof stops strategically placed to selectively restrict the movement ofthe dogs through interference therewith. In the present embodimentblocks 104 and 106 provide such stops. The blocks 104 and 106 are placedon an actuation member or shaft 108 in such a manner that the longestdimension of one block is perpendicular to the longest dimension of theother. The blocks 104 and 106 and the shaft 108 are capable of rotating90 in order to allow for the positioning of each of the blocks 104 and106 in a horizontal position. When either of the two blocks 104 or 106is horizontally disposed, it operates to prevent the dogs 72 fromrotating in one direction. Because the blocks 104 and 106 areperpendicularly oriented, when one of the two blocks is horizontallydisposed so as to prevent rotation of the dogs 72 in a first direction,the other block is vertical and thereby allows rotation of the dogs 72in the opposite direction. The two modes provided by rotation of theblocks 104 and 106 are shown in FIGS. 5 and 6. The shaft 108 ispivotally mounted in bearing 110. Spacer collar 112 helps to properlyposition the shaft 108 in the walking beam. The bearing is welded tostructural support plate 114 which extends across the advancementmechanism 10 between rails 16. A lever 116 is mounted on the end ofshaft 108. Hole 118 accepts bolt 120 which acts to hold the lever 116and the shaft 108 in place. Circular guide 122 is fastened to the baseplate 22 by bolts 124. Circular guide 122 extends beyond the structuralmember 114 and base plate 22 to provide interference with the lever 1l6. Notches 126 are provided in the extended portion of the guide 122vertically above the center of shaft 108 and at 45 in either directiontherefrom. Lever 116 is positioned 45 from the longest dimension of eachblock 104 and 106 in order that one or the other of blocks 104 and 106will be horizontally disposed when the lever 116 is in either of thenotches 126 located 45 from the vertical. When the lever 116 is in thecenter notch 126, the blocks 104 and 106 are each rotated 45 fromvertical. In this position, both blocks 104 and 106 interfere with therotational motion of the dogs 72 which in turn prevents thedisengagement of the dogs 72 from the rails 16 in either direction.

A hydraulic cylinder 18 of the double action type provides means forboth extension and retraction of the advancement mechanism 10 toaccomplish the walking process. The cylinder 18 is driven by pump 128.It is advantageous to use a variable volume pump to provide relativelyrapid displacement of the cylinder 18 under low load conditions and arelatively large pressure output with a correspondingly smaller travelof the cylinder 18 under high load conditions. The pump swash plateshaft 130 is coupled with shaft extension 132 and subsequently throughtie rod 134 to control lever 136. The control lever 136 is pivotallymounted to the structure of the boring unit 12. Rotation of the controllever 136 from the vertical determines the direction of flow through thepump and the magnitude of volume per cycle.

There are forces inherent in a variable volume pump which drive the pumpswash plate shaft 130 to the neutral position when great resistance tohydraulic flow is experienced. Through proper alignment and bearingtolerance, the frictional resistance between the pump swash plate shaft130 and the control lever 136 can be reduced below the level of theseinherent forces. When the cylinder 18 reaches the limit of either anextension or a contraction stroke, the pump swash plate shaft 130 andnecessarily the control lever 136 will be accelerated to the neutralposition. Because of the inherent mass in the shaft 130, extension 132,connectors 134, and control lever 136, the control lever 136 has beenfound to continue to oscillate through multiple cycles of the walkingprocess until the boring unit 12 or the advancement mechanism 10 itselfencounters high resistance to travel.

When this totally automatic feature is not desired, resistance arm 138can be swung into interference with the control lever 136. Theresistance arm 138 is pivotally mounted to the-structure of the boringunit 12 and has a plate 140 which extends into the path of the controllever 136. A notch 142 is provided on the plate 140 to catch and retainthe control lever 136 as it travels toward the neutral position when anexcessive resistance is encountered by the pump 128. Because the plate140 partially extends into the path of the lever 136, it providesfrictional resistance to relative movement between the control lever 136and the structure of the boring unit 12.

The overall operation of the unit is provided by positioning lever 116so that block 104 is in the horizontal position. With block 104 in thisposition, the dogs 72 are free to rotate only as shown in FIG. 5. 'Withthe dogs 72 locked in the first set of slots 20, the cylinder 18 isexpanded. The expansion of the cylinder 18 causes the earth boring unit12 to advance along the rails 16. When the cylinder 18 has reached fullextension, the hydraulic flow through the pump 128 is reversed and thecylinder 18 contracts. Because of the relative weight of the boring unit12 as compared to the advancement mechanism 10, the advancementmechanism is pulled toward the unit 12. As the advancement mechanism 10is drawn toward the unit 12, the dogs 72 rotate from the slots and slidealong the rails 16. When the cylinder 18 is near the end of itscontraction stroke, the next slots 20 are encountered by the dogs 72which rotate into the engagement position. It is necessary that thecylinder stroke 18 is slightly longer than the distance between slots 20as the dogs 72 must pass beyond the slots 20 before they are clear torotate into the engagement position. When engaged, the pump 128 is thenreversed and the cylinder commences to expand. Because the dogs 72 areprevented from rotating by block 104, they remain in the engagedposition and hold the advancement mechanism 10 fixed relative to therails 16. Consequently, the earth boring unit 12 is again advanced in asecond cycle of'the walking operation. The same sequence operates forretraction of the unit 12 by rotating lever 116 90. This places block106 in the horizontal position as shown inFlG. 6. When the operatordesires to alternately advance and retract the unit 12 through a shortdistance, the lever 116 is positioned vertically to bring blocks 104 and106 into simultaneous interference with dogs 72. With the lever 116 inthe vertical position, the dogs 72 are unable to rotate in eitherdirection and the advancement mechanism 10 is consequently held fixedrelative to the rails 16. To utilize the totally automatic feature ofthis device, interference arm 138 is rotated from the path of thecontrol lever 136. in this location, the control lever 136 is free tooscillate and automatically reverse the travel of the cylinder 18 ateach end of its stroke. Because this feature is only available when thepump is only partially loaded, it can only be used for retraction of theunit 12 or advancement of the unit 12 until the auger 14 encounters theearth.

Thus, the advancement mechanism 10 is capable of operation with a singlesetting of the control lever 116 and does not require a separateunlocking operation for each cycle of the walking motion. Once thedirection of travel is determined through the operation of lever 116,the total walking operation is controlled by control lever 136. Further,the walking operation may be totally automated under certaincircumstances as noted above.

Having fully described my invention, it is to be understood that l amnot to be limited to the details herein set forth but that my inventionis of the full scope of the appended claims.

I claim: l. An advancement mechanism for a horizontal earth 5 boringmachine supported on rails and comprising a base capable of being movedalong the rails in first and second directions, rigid members pivotallymounted to said base and extending to the rails, and means on the railsfor engaging said rigid members with the rails, said engaging meansallowing pivotal movement of said rigid members into and out ofengagement with the rails when said base is moved in said firstdirection and said engaging means allowing pivotal movement of saidrigid members into and out of engagement with the rails when said baseis moved in said second direction, and stops movably mounted on saidbase capable of being positioned to selectively interfere with pivotalmovement of said rigid members to constrain said members when inengagement with said means. 2. The deviceof claim 1, wherein said stopsinclude a shaft pivotally mounted to said base, and two blocks fixed tosaid shaft, said shaft and said blocks being positioned to pivot intothe pivotal path of said rigid members. 3. The device of claim 1,wherein the advancement mechanism further comprises means for drivingsaid base, said driving means including a hydraulic cylinder operablyfixed to said advancement mechanism and to the horizontal earth boringmachine, a variable volume pump hydraulically connected to saidcylinder, and means for controlling the volume and the direction of flowof said pump. 4. The device of claim 3, wherein said control meanscomprises a lever arm of sufficient mass to carry by its momentum saidvariable volume pump into a reversed flow mode when said cylinderreaches each end of its stroke. 5. An advancement mechanism for ahorizontal earth boring machine supported on rails and comprising abase, means mounted to said base for engaging the rails to selectivelylock the base thereto, means for driving said base, including ahydraulic cylinder fixed at one end to said base and to the horizontalearth boring machine at a second end, a variable volume pumphydraulically connected to said cylinder, and means for controlling thevolume and direction of flow of said pump, said control means includinga lever arm of sufficient mass to carry by its momentum said variablevolume pump into a reversed flow when said cylinder reaches each end ofits stroke. 6. An advancement mechanism for horizontal earth boringmachines supported on rails and comprising a base positioned on therails and capable of being moved along the rails in first and seconddirections, rigid members pivotally mounted to said base and extendingto the rails, slots provided on the rails for receiving said rigidmembers for engaging said rigid members with the rails, said slotsallowing pivotal movement of said rigid members into and out ofengagement with the when in engagement with said slots, means fordriving said base including a hydraulic cylinder operably fixed to saidadvancement mecha-- nism to the horizontal earth boring machine, avariable volume pump hydraulically connected to said cylinder, and meansfor controlling the volume and direction of flow of said pump.

1. An advancement mechanism for a horizontal earth boring machinesupported on rails and comprising a base capable of being moved alongthe rails in first and second directions, rigid members pivotallymounted to said base and extending to the rails, and means on the railsfor engaging said rigid members with the rails, said engaging meansallowing pivotal movement of said rigid members into and out ofengagement with the rails when said base is moved in said firstdirection and said engaging means allowing pivotal movement of saidrigid members into and out of engagement with the rails when said baseis moved in said second direction, and stops movably mounted on saidbase capable of being positioned to selectively interfere with pivotalmovement of said rigid members to constrain said members when inengagement with said means.
 1. An advancement mechanism for a horizontalearth boring machine supported on rails and comprising a base capable ofbeing moved along the rails in first and second directions, rigidmembers pivotally mounted to said base and extending to the rails, andmeans on the rails for engaging said rigid members with the rails, saidengaging means allowing pivotal movement of said rigid members into andout of engagement with the rails when said base is moved in said firstdirection and said engaging means allowing pivotal movement of saidrigid members into and out of engagement with the rails when said baseis moved in said second direction, and stops movably mounted on saidbase capable of being positioned to selectively interfere with pivotalmovement of said rigid members to constrain said members when inengagement with said means.
 2. The device of claim 1, wherein said stopsinclude a shaft pivotally mounted to said base, and two blocks fixed tosaid shaft, said shaft and said blocks being positioned to pivot intothe pivotal path of said rigid members.
 3. The device of claim 1,wherein the advancement mechanism further comprises means for drivingsaid base, said driving means including a hydraulic cylinder operablyfixed to said advancement mechanism and to the horizontal earth boringmachine, a variable volume pump hydraulically connected to saidcylinder, and means for controlling the volume and the direction of flowof said pump.
 4. The device of claim 3, wherein said control meanscomprises a lever arm of sufficient mass to carry by its momentum saidvariable volume pump into a reversed flow mode when said cylinderreaches each end of its stroke.
 5. An advancement mechanism for ahorizontal earth boring machine supported on rails and comprising abase, means mounted to said base for engaging the rails to selectivelylock the base thereto, means for driving said base, including ahydraulic cylinder fixed at one end to said base and to the horizontalearth boring machine at a second end, a variable volume pumphydraulically connected to said cylinder, and means for controlling thevolume and direction of flow of said pump, said control means includinga lever arm of sufficient mass to carry by its momentum said variablevolume pump into a reversed flow when said cylinder reaches each end ofits stroke.